Sewing machine loop-taker mechanism



OctQlZ, 1 937. I w M YERs- I 1 1 smgmemxbama-mm TAKER MECHANISM OriginalFiled April 16, 1936 3 Sheefos-Sheet 1 Oct. 12, 1937. w. MYERS 2,095,450

SEWING MACHINE LOOP -TAKER MECHANISM Original Filed April 16, 19 36 3SheetQ-Sheej 2 if a. I

1a In Oct. 12, 1937. w. MYERS,

SEWING MACHINE LOOP TAKER MECHANISM- Original Filed April 16, 1936 3Sheets-Sheet 3 v aw w 1.; 6 A 17/0? Patented Oct. 12, 1937 SEWINGMACHINE LOOP-TAKER MECHANISM Walter Myers, Bridgeport, Conn., assignorto The Singer Manufacturing Company, Elizabeth, N. J., a corporation ofNew Jersey Original application April 16, 1936, Serial No.

Divided and this application January 19, 1937, Serial No. 121,251

7 Claims.

This invention relates to improvements in stitch-forming mechanisms forsewing machines and has for its primary object to provide supporting andactuating means for a sewing machine loop-taker, more specifically ofthe verticalaxis rotary hook type, which is particularly adapted forhigh speed operation.

With the .above and other objects in view, as will hereinafter appear,the invention comprises the devices, combinations and arrangements ofparts of a loop-taker actuating mechanism described in connection withthe accompanying drawings which illustrate a preferred embodiment of theinvention and in which:

Fig. 1 represents a vertical longitudinal section, partly in frontelevation, ofasewing machine containing the present improvement. Fig.2'is a bottom plan view of the machine. Fig. 3 represents an enlargedtransverse section of the bed-plate, substantially on the line 3--3 ofFig. 2. Fig. 4 represents a perspective view, partly in section, of oneof the rotary-hook brackets, including a portion of the rotary hookmechanism thereof. Fig. 5 is a top-plan, partly in section, 25 of theadjacent rotary hook brackets. Fig. 6

represents a section of one of the rotary-hook brackets, insubstantially a plane containing the vertical axis of the hook-shaft.Fig. 7 represents a horizontal section of the hook-bracket,

30 substantially on the line of Fig. 6.

As described in my co-pending patent application Serial No. 74,615,filed April 16, 1936, of which this application is a division, and as11- lustrated in the accompanying drawings, the present invention hasbeen embodied in a sewing machine having a frame comprising aworksupporting bed-plate I provided with left and right slide-plates 2and 3 and with a throat-plate 4 between said slide-plates. Rising fromone end projecting from the bracket-arm 8. The main shaft 8 is alsojournaled in a bearing bushing l2 and, at its end adjacent said bushing,carries a crank |3 connected by the usual link M with a needle-bar l5carrying at its lower end a pair of .needles' l6 arranged abreast withrespect to the direction of feed of the work.

The needle-bar I5 is journaled for vertical reof the bed-plate is thehollow standard 5 of aciprocation in a pendulous frame I1 pivotally hungupon a taper-headed fulcrum-pin I8 for.

j PATENT. OFFICE swinging movements within the head labout an 3 axissubstantially parallel to the axis of rotation of the main-shaft 8, saidfulcrum-pin being se-- cured by a screw I8 threaded into the head I.

Disposed below and adjacent the rearward edge of the bed-plate I,substantially parallel to the main-shaft 8, is a loop-taker. andfeed-actuating shaft l9. Adjacent one end thereof, the shaft I9 isjournaled in a ball-bearing sustained by a'bearing-lug 2| depending fromthe bed-plate At its opposite end, theshaft I9 is journaled in abearing-bushing 22 secured in a lug 23 depending from the bed-plate andin termediate its ends the shaft I9 is journaled in I anotherbearing-bushing 24 secured in a lug 25 ends of the bearing-bushings 22and 24, are two' spiral-gears 29 and 30 in driving engagement withspiral-gears 3| and 32, respectively, the gear ratios being such thatthe driven gears 3|, 32 are rotated at twice the speed of the drivinggears 29, 30. The driven gears 3|, 32 are carried by vertically disposedloop-taker shafts 33, 34, respectively, said shafts being of similarconstruction and each carrying at its upper end a looptaker 35, or 36,of the vertical-axis rotary hooktype. These loop-takers cooperate withthe needles I6 in the formation of lock-stitches; the needle-threadloops seized by the loop-takers being each cast about a lower threadmass contained in a bobbin-case 31, journaled in the respectiveloop-taker and restrained against rotation therewith by a suitablestop-notch 38 at the under side of the throat-plate 4.

The loop-taker shaft 33 is journaled in verfrom a left-handloop-taker'brackt 4|, said bracket 4| having at its rearward end a splitbearing-boss 42 adjustably clamped -uponv the bushing 22 by a screw 43.At its forward e'nd,;fv the bracket 4| is provided with a foot44 havinga rounded upper face secured by a screw 45 against a seat aiiorded bythe horizontallytflattically spaced bearing-lugs 39 and 40 projectingtened lower end of a lug 48 depending from the bed-plate I. Thebracket-securing screw 45 passes through a slot 4! provided in the foot44, said slot being elongated in a direction to provide for adjustmentof the bracket 4i toward and from the path of needle reciprocation.

The loop-taker shaft 34 is likewise journaled in vertically spacedbearing-lugs 48 and 49 projecting from a right-hand loop-taker bracket58, said bracket 58 having at its rearward end a split bearing-boss 5iadjustably clamped by a screw 52 upon the bushing 24. At its forwardend, the bracket 58 is provided with a foot 53 having an elongated slot5d entered by a screw 55 which secures the foot 53 against a horizontalseat 55 formed by suitably recessing a lug 57 depending from thebed-plate I.

The loop-taker shafts 33 and 34 are similarly journaled in the bracketsH, 58. Referring more particularly to Figs. 6 and '7 of the drawings,the upper bearing-lug 48 of the bracket 58 has a vertical aperture 48'.Threaded into said aperture from the under side thereof is a bushing I53secured in set position by a screw l54. The bushing I53 provides a seatfor and serves to vertically locate an outer race-ring 58, which ispreferably force-fitted to its seat and is thereby restrained againstrotation. An inner race-ring 59 closely embraces the shaft 34 and ispreferably caused to rotate with said shaft by a clutchball 68 disposedwithin said race-ring 59 and in a recess 8i peripherally provided in theshaft 34. The base of the recess BI is preferably a plane surface and isformed so that the depth of said recess, medianly of its length, ispreferably substantially equal to the diameter of the ball 68, toprovide for assemblage of the parts. Upon rotation of the shaft 34, theball 68 will instantly grip the inner race-ring 58 and will inducerotation with the shaft of the inner racering. This arrangementfacilitates securing the inner race-ring to its shaft and obviates thedistortion of the parts likely to occur by employment of ring-securingscrews. A series of bearing-balls 62 is interposed between the racerings58 and 59 in the usual manner to complete the upper ball-bearing of theloop-taker shaft 34.

Resting upon the inner race-ring 59 is an oilguard washer 63 which isundercut to overhang the outer race-ring 58 in spaced relation thereto,thereby providing a clearance-recess 64 above said race-rings forsupplying lubricant to the bearing-balls 62. The washer 63 is held inplace by an eccentric 65 formed or otherwise provided upon the shaft 36directly below the loop-taker 36, said washer serving to guard againstemission of lubricant from the upper end of the bearinglug aperture 48.

The eccentric 65 is embraced by the strap of a short pitman 68 pivotallyconnected by a stud-bolt B1 to a horizontally vibratory arm 68 of anangular opener-carrier 68, 68. The arm 68 of the carrier is disposed ina suitably shaped cavity III provided in the upper face of the bracket58, one end of said arm 68 being pivotally secured by a fulcrum-stud Hfixed in the bracket 58 by a set-screw I2. disposed arm 69 of theopener-carrier extends above the bracket 58 and is horizontally groovedin its upper end to provide a seat for the shank of the usualopener-finger I3 adapted to engage intermittently and oscillate thebobbin-case 3?, thereby to open a thread-passage in the bobbincaserotation restraining means. The shank of the finger E3 is slotted toreceive a finger-secur- The vertically ing .screw I4 and to provide foradjustment of said finger.

The lower end of the loop-taker shaft 34 is journaled in an aperture 49'provided in the bearing-lug 49, said aperture 49' being in verticalalinement with the upper lug aperture 48'. Similarly to the upperball-bearing, the lower ball-bearing includes a series of balls I5disposed between a fixed outer race-ring I8 and an inner race-ring H,the inner race-ring 11 embracing and being caused to rotate with theshaft 34 by a clutch-ball I8 disposed in a recess T9 peripherallyprovided in said shaft. The outer race-ring is vertically located by abushing I55 threaded into the lower lug from the under side thereof,said bushing being secured in set position by a screw I 56. Overlyingthe lower ballbearing is an undercut oil-guard washer 80 similar to theupper-bearing washer B3 and defining a clearance-recess BI above theball-bearing for supplying lubricant to the bearing-balls I5. The washer80 is held in place by the hub of the driven gear 32, disposedbetween-the bracketlugs 48, 49 and secured to the shaft 34 by a setscrew82.

The journaling of the loop-taker shaft 33 in thebearing-lugs 39, 48 ofthe bracket M and the bobbin-case opener mechanism actuated by saidshaft 33 correspond in detail with the described journaling of the shaft34 and its bobbincase opener mechanism. Accordingly, the parts have beencorrespondingly designated in the drawings, so far as illustrated indetail.

Lubricant is supplied to the bearings of the loop-taker shaftsfromreservoirs carried by the respective loop-taker brackets and connectedby separate conduits with the shaft bearings. Referring moreparticularly to Figs. 4 and 5 of the drawings, the bracket H, forexample, is preferably integrally provided with a trapezoidallubricant-supply reservoir 83 disposed adjacent to the opener-mechanismcavity 10 in said bracket. The rearward portion of the reservoir 83 isclosed at the top by an overhanging roof-wall 83, which is preferablyintegral with the side walls of the reservoir and terminates short ofthe forward wall, thereby to provide a top opening 84 in the forwardportion of the reservoir. The roof-wall 83 functions to retain lubricantwithin the reservoir 83 when the sewing machine is tilted back foraccess to the mechanism below the bed-plate I. Preferably, alubricant-absorbent pad 85 is placed upon the bottom of the reservoir 83to control the flow of lubricant therefrom.

The bottom of the reservoir 83 has an aperture 86 opening into an oilduct 81 provided in the bracket 4i below and extending horizontallycrosswise of the front end of said reservoir. The outer end of the duct81 is sealed by a plug 88 and its inner end is connected with ahorizontal duct 88, provided in the bracket-bearing lug 39 and extendingtransversely of the duct 81. The outer end of the connecting duct 89 issealed by a plug 58 and its inner end terminates in a reduced bore 89'communicating with the clearance-recess 64 above the shaft-bearing balls62.

The bottom of the reservoir 83 has another aperture constituting theupper end of a vertical duct 9I provided in the bracket 4|. The lowerend of said duct 8i opens into a horizontallytransverse bracket-duct 92closed at its outer end by a plug 93. At its inner end, the duct 92 hasa restricted bore 94 in the bracket-lug 48, said bore 94 communicatingwith the clearancerecess 8i above the shaft-bearing balls 15.

aoeaico before referred to and, as the present invention is not limitedto any specific form of feeding mechanism, it is deemed uncssential todescribe the same.

Having thus,set forth the nature of the in vention what I claim hereinis:-

1. Loop-taker mechanism for sewing machines, comprising, a supportingbracket having vertically spaced bearing-lugs, a vertically disposedlooptaker carrying shaft, ball-bearings infsaid lugs providingvertically spaced journals for said shaft, driving connections forrotating said shaft,-

a lubricant-supply reservoir in said'bracket adjacent to and connectedwith the upper of said ballbearings, and means for conducting lubricantfrom said reservoir to the lower of said ball-bearings. I

2. Loop-taker mechanism for sewing mach nes, comprising, a supportingbracket having vertical- 1y spaced bearing-lugs, a vertically disposedlooptaker carrying shaft, ball-bearings in said lugs providingvertically spaced journals for said shaft, driving connections forrotating said shaft, a lubricant-supply reservoir upon said brackethaving a roof wall closing the upper rearward portion of the reservoirand leaving the front portion of said reservoir open at the top, andmeans for conducting lubricant from said reservoir to saidball-bearings.

3. Loop-taker mechanism for sewing machines, comprising, a supportingbracket having vertically spaced bearing-lugs provided with verticallyalined apertures, a vertically disposed looptaker carrying shaftperipherally provided with vertically spaced recesses, ball-bearingsdisposed in the apertures of said lugs and providing vertically spacedjournals for said shaft, said ballbearings including outer race-ringsfixed in the respective bearing-lugs and inner race-rings embracing saidshaft recesses, clutch-balls disposed in said shaft recesses foreffecting rotation of said inner race-rings with said shaft, and drivingconnections for rotating said shaft.

4. Loop taker mechanism for sewing machines, comprising, a supportingbracket having vertically spaced bearing-lugs provided with verticallyalined apertures, bushings threaded into said lugs, a verticallydisposed loop-taker carrying shaft, ball-bearings disposed in theapertures of said lugs and providing vertically spaced journals for saidshaft, said ball-bearings including outer race-rings engaged andvertically located by said bushings,'means for securing said bushings,and driving connections for rotating said shaft.

5. Loop-taker mechanism for sewing machines, comprising, a supportingbracket having vertically spaced bearing-lugs provided with verticallyalined apertures, a vertically disposed looptaker carrying shaft,ball-bearings disposed in the apertures of said lugs and providingvertical- 1y spaced journals for said shaft, means includinga bushingthreaded into one of said lugs for locating said ball-bearingsinvertically spaced relationship, and driving connections forrotating saidshaft.

6. Loop-taker mechanism for sewing machines, comprising, a supportingbracket having vertically spaced bearing-lugs provided with vertical .lyalined apertures, a vertically disposed looptaker carrying shaft,ball-bearings disposed in the apertures of said lugs and, providingverti cally spaced journals for said shaft, bushings disposed in saidbearing-lug apertures below and in engagement with said ball-bearings,and driving connections for rotating said shaft.

7. Loop-taker mechanism for sewing machines, comprising, a supportingbracket having vertically, spaced bearing-lugs provided with verticallyalined apertures, a vertically disposed looptaker carrying shaft,ball-bearings disposed in the apertures of said lugs and providingvertically spaced journals for said shaft, a bushing disposed in one ofsaid bearing-lug apertures and providing a positioning shoulder for oneof said ball-bearings, and driving connections for rotating said shaft.

WALTER.

